feat: upgrade to x/tools 0.28

cl/_testdefer/firstloop1/out.txt

@@ -1,7 +1,7 @@
  0: always
  6: cond
- 3: loop
  1: loop
+ 2: loop
  4: loop
- 2: cond
+ 3: cond
  5: cond

cl/_testdefer/firstloop2/out.txt

@@ -1,4 +1,4 @@
  0: always
- 3: loop
  1: loop
- 2: always
+ 2: loop
+ 3: always

cl/_testdefer/loop/out.txt

@@ -1,7 +1,7 @@
  0: always
  1: cond
- 4: loop
  2: loop
+ 3: loop
  5: loop
- 3: cond
+ 4: cond
  6: cond

cl/_testdefer/print/out.txt

@@ -8,11 +8,11 @@
 10: loop
  8: loop
  9: cond
-13: loop
 11: loop
-12: cond
+12: loop
+13: cond
 14: cond
  2: cond
-17: loop
 15: loop
-16: always
+16: loop
+17: always